1. Field of the Invention
The present invention relates to a battery unit and a battery pack having improved conductivity and improved contacts along the charging and discharging paths, leading to improved battery efficiency.
2. Description of Related Art
Due to the advantages thereof, secondary batteries are applied to various technical fields and are used as an energy source in mobile electronic appliances such as digital cameras, cellular phones, laptop computers, etc. Moreover, secondary batteries are noticed as an energy source in hybrid electric vehicles, which are suggested as a solution for solving air pollution caused by conventional internal combustion engines that use fossil fuels such as gasoline and diesel.
Along the charging and discharging paths of battery units are lead tabs and lead members electrically connected to the lead tabs. I have noticed that this connection between the lead tab and the lead member is made by a weld. The welding process generates a lot of heat, thereby causing damage to nearby components. Also, I have noticed that the integrity of welds is not always adequate, as the bonding strength may be limited and the surface area of the weld may be limited. As a result, what is needed is an improved design and method of attaching the lead members to the lead tabs that does not disrupt or threaten other components of the battery while providing a stronger, less resistant contact by increasing the surface area of contact.